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A theoretical analysis is presented of peristaltic pumping down a narrow conduit with permeable walls, motivated by the flushing action of lugworms and other marine organisms in sandy burrows. Flow in the conduit is dealt with using lubrication theory; the leakage into the surrounding medium is taken into account by exploiting slender-body theory to solve the associated Darcy problem. By adopting a model for the local force balance on the pumping surface, we bridge between the limits in which the pump operates with either fixed load or displacement. In the latter limit we characterize peristaltic waves with either fixed form or ones that partially collapse the conduit. We construct pump characteristics (the relation between the mean flux and net pressure drop) when the burrow wall is impermeable and pressures are fixed at each end, and compare the results with existing laboratory experiments performed on lugworms. We then consider how the peristaltic dynamics is changed when the wall is made permeable. Last, we consider pumping along an impermeable burrow into a leaky head shaft. The results reveal that the permeability of the conduit wall or end can greatly impact the direction and strength of the recirculating flow. [ABSTRACT FROM AUTHOR]

Fluorination of single-wall carbon nanotubes (SWCNTs) was performed by using the CF4 radio-frequency plasma technique. The structural and bonding properties of the plasma-processed SWCNTs were investigated by transmission electron microscopy, x-ray photoelectron spectroscopy, and Raman spectroscopy. The plasma parameters, i.e., self-biased voltage, plasma ion density, and ion dose, substantially affected the structural and bonding properties of plasma-processed SWCNTs. We show that sidewall fluorination of SWCNTs occurs in CF4 plasma at low self-biased voltages. Plasma conditions for the sidewall fluorination of SWCNTs are discussed. [ABSTRACT FROM AUTHOR]

The C[F.sub.4] radio-frequency plasma technique is used for performing the fluorination of single-wall carbon nanotubes (SWCNTs). The studies have shown that sidewall fluorination SWCNTs has occurred in C[F.sub.4] plasma at low self-biased voltages.

The frequency of either CD4–8– (double negative; DN) or CD4+ V α24+V β11+ NKT cells, the expression of CD1d and the binding of CD1d-tetramer loaded with α-galactosylceramide ( α-GalCer) to NKT cells were analysed in peripheral blood mononuclear cells (PBMCs) of patients with Wegener's granulomatosis (WG), relapsing polychondritis (RP) and healthy subjects (HS). DN and CD4+ V α24+V β11+ NKT cells as well as CD1d- α-GalCer tetramer-positive NKT cells, were significantly decreased in number in both WG and RP patients compared to those from HS. When cytokine profiles were analysed in these PBMCs upon stimulation with phorbol ester and calcium ionophore, CD4+ T cells from patients with WG and RP exhibited a Th1 bias, whereas CD4+ NKT cells from WG patients in remission showed a Th2 bias. These findings suggest that NKT cells (especially CD4+ NKT cells) play a regulatory role in Th1 autoimmunity in patients with WG and RP. The reduction in NKT cell counts appears to be associated with the low responsiveness to α-GalCer. The dysfunction of NKT cells to recognize ligands such as α-GalCer may also contribute to the defects observed in NKT cells from WG and RP patients. [ABSTRACT FROM AUTHOR]